This sensitive bio-monitoring circuit was found in the December 1984 issue of Radio Electronics magazine. The circuit is powered by a 9 V battery and uses a low-impedance headphone output.
The power transistor of this circuit can also be the TIP42 mounted on a good heat sink. The...
Using a window comparator, this circuit trips over a certain range of input voltages. Formulas for...
This timer circuit was found in a 1980s documentation. The integrated circuit is the 555, which...